scholarly journals The feasibility of Cassia fistula gum with polyaluminium chloride for the decolorization of reactive dyeing wastewater

2015 ◽  
Vol 80 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Yuan Perng ◽  
Manh Bui

In order to find a new environmental-friendly coagulant that can partially replace conventional polyaluminium chloride (PAC) which was shown to be toxic to aquatic environment, gum extracted from seeds of Cassia fistula Linn. (CF) was investigated in decolorization of reactive dyes Blue 19 (RB19) and Black 5 (RB5) using jar-test experiments. The optimal results showed that crude CF gum (at pH 10, initial dye concentrations (IDC) of 100 and 50 mg L-1, gum dosages 200 and 300 mg L-1, reaction time 30 and 45 min, and agitation speed 60 rpm) did not achieve high degrees of decolorization in RB5 and RB19 (55.7 and 62.0 %, respectively) as compared with PAC coagulant (97.2 and 94.4 %, respectively) at the same IDC and reaction time. Whereas when CF gum was used in combination with PAC, decolorization efficiencies of both dyes reached over 92 % at 40 % volume fraction of gum. These results indicated the potential of using CF gum as a ?green? coagulant or as a contributing factor to color removal of textile wastewater.

2014 ◽  
Vol 5 (1) ◽  
pp. 8-11
Author(s):  
Yuan-Shing Perng ◽  
Ha Manh Bui

Color removal of some reactive dyes (Blue 19, Black 5 and Red 195) using a local Poly Aluminium Chloride (PAC) was investigated with Jar-test experiment. The dyes were removed (above 94%) at optimal pH 7 (Red 195) and pH 10 (Blue 19 and Black 5). The PAC dosage of 220 mg/L(Blue 19 and Black 5) and 160 mg/L (Red 195) were found to be best for decreasing dye up to 50 mg/L (Black 5, Red 195) and 100 mg/L (Blue 19). Reaction time and agitation speed also affected the decolorization process. That result indicates that Vietnamese PAC can be a robust and economical coagulant for discolorization of reactive dyeing process. Chất keo tụ Poly Aluminium Chloride (PAC) sản xuất tại Việt nam được ứng dụng khử màu của một số màu nhuộm hoạt tính phổ biến (Blue 19, Black 5 and Red 195) trên thí nghiệm Jar-test. Kết quả cho thấy màu bị loại gần như hoàn toàn (trên 94 %) tại pH 7 (Red 195) hoặc 10 (Blue 19 và Black 5). Nồng độ PAC đạt hiệu quả tốt nhất tại 220 mg/L (Blue 19 và Black 5) và 160 mg/L (Red 195) ứng với nồng độ màu 50 mg/L (Black 5, Red 195) hay 100 mg/L (Blue 19). Thời gian phản ứng, tốc độ khuấy cũng có tác động đến hiệu suất khử màu. Kết quả nghiên cứu cho thấy PAC sản xuất tại Việt nam không những là một chất keo tụ tốt mà còn rất kinh tế cho việc khử màu hoàn toàn trong nước thải nhuộm hoạt tính.


2014 ◽  
Vol 5 (1) ◽  
pp. 27-31
Author(s):  
Yuan-Shing Perng ◽  
Ha Manh Bui

This paper presents the result of dyeing solution coagulation with the use of ferrous ammonium sulfate hexahydrate (FAS). The examined solution contains two reactive dyes: Black 5 and Blue 19. It has been shown that the efficiency of the dye removal depends on the type of dye, coagulation dosage and the initial pH. Our result showed that the increase of initial pH up to 12 enhanced the color removal efficiency; the FAS dose was determined 280 ml (Black 5) and 180 mg/l (Blue 19) at slow mixing time 15 min, agitation speed 60 rpm, and the initial dye concentration should be 50 and 100 mg/L for Black 5 and Blue 19, respectively. Chất keo tụ sắt (II) amoni sulfate (FAS) được sử dụng khử màu của hai màu nhuộm hoạt tính phổ biến (Blue 19 và Black 5). Kết quả cho thấy, quá trình keo tụ bị ảnh hưởng nhiều bởi loại màu nhuộm, nồng độ chất keo tụ và pH của dung dịch đầu vào. Với nồng độ FAS 280 mg/l (Black 5) và 180 mg/l (Blue 19), pH đầu vào dung dịch khoảng 12, thời gian phản ứng 15 phút, tốc độ khuấy 60 vòng/phút ứng với nồng độ màu Black 50 mg/L và blue 100 mg/L dung dịch gần như mất màu hoàn toàn.


2012 ◽  
Vol 19 (2) ◽  
pp. 163-174
Author(s):  
Stanisław Ledakowicz ◽  
Lucyna Bilińska ◽  
Renata Żyłła

Application of Fenton's Reagent in the Textile Wastewater Treatment Under Industrial Conditions Application of reactive dyes is very popular in textile industry as these dyestuffs are characterized by good fastness properties. Constapel et al in 2009 estimated the production of this type of dyes for over 140,000 Mg/year. The reactive dyes are mostly (50%) employed for coloration of cellulosic fibers, however they can also be applied on wool and nylon. Unfortunately, they possess a low degree of fixation (50÷90%), since the functional groups also bond to water, creating hydrolysis and the excess of dyes applied cause a colored pollution of aqueous environment. Moreover, dyeing process requires the use of: electrolytes in the form of aqueous solutions of NaCl or Na2SO4 in the concentration up to 100 g/dm3, alkaline environment (pH > 10) and textile auxiliary agents (including detergents). Therefore, the wastewater generated during the reactive dyeing processes is characterized by high salinity, pH value and color, and due to low value of the BOD5/COD ratio are nonbiodegradable. The successful methods of textile wastewater treatment could be Advanced Oxidation Processes (AOPs), amongst which the Fenton reagent seems to be most promising as it is the cheapest and easy in use. Based on the newest literature survey it was found that many successful tests with Fenton reaction were performed mainly in decolorization. However, not enough attention was devoted to decolorization of real industrial wastewater containing dyes, detergents and salts NaCl, or Na2SO4. The experiments carried out in a laboratory scale were focused on the impact of NaCl and textile auxiliary agent (liquid dispersing and sequestering agent) on an inhibition of decolorization process by Fenton's reagent. The objects of the investigation were synthetic mixtures simulating the composition of real textile wastewater as well as the real industrial wastewater generated in the reactive dyeing. The inhibition of the Fenton decolorization in the presence of NaCl and liquid dispersing and sequestering agent was demonstrated. Additional experiments using pulse radiolysis were carried out in order to confirm the inhibition of chloride in the decolorization process.


2013 ◽  
Vol 60 (1) ◽  
Author(s):  
Norzita Ngadi ◽  
Noor Yahida Yahya ◽  
Nabilah Muhamad

Dalam kajian ini, poliacrylamid (PAM) dan polialuminium klorida (PAC) telah digunakan sebagai bahan pengental untuk merawat air sisa industri tekstil. Eksperimen ini telah dijalankan dengan menggunakan ujian balang. Kesan dos, kelajuan percampuran dan masa pemendapan ke atas keberkesanan proses flokulasi telah dikaji. Air sisa yang terawat dianalisis untuk penyingkiran warna, pengurangan COD dan pengurangan kekeruhan. Keputusan yang diperolehi menunjukkan bahawa PAM adalah lebih baik daripada PAC dalam merawat air sisa tekstil. PAM mencatatkan penurunan parameter tertinggi, iaitu 6 NTU untuk kekeruhan, 744 mg / l untuk COD, dan scala kurang daripada 0.5 untuk warna. Prestasi tebaik PAM dicapai pada dos 0.07 g dan apabila proses flokulasi dijalankan pada 200 rpm kelajuan percampuran dan 30 min masa pemendapan. Kajian ini juga mendapati bahawa parameter operasi yang dikaji (iaitu dos, kelajuan percampuran dan masa pemendapan) tidak banyak mempengaruhi ke atas penyingkiran warna, dan penurunan kekeruhan dan COD apabila PAC digunakan sebagai bahan pengental. Kata kunci: Pengelompokan; poliacrylamid (PAM); polialuminium klorida (PAC); air sisa tekstil In this study, polyacrylamide (PAM) and polyaluminum chloride (PAC) was used as a flocculant to treat industrial textile wastewater. The experiment was conducted using a Jar test experiment. The effect of dosage, mixing speed and settling time on the performance of the fflocculation process was investigated. The treated textile wastewater was analyzed by its color removal, turbidity and COD reductions. The results obtained showed that PAM performed better in treating the textile wastewater compared to PAC.PAM recorded the highest reduction of parameters, which are 6 NTU for turbidity, 744 mg/l for COD, and scale less than 0.5 for colour. The best performance of PAM was achieved at dosage 0.07 g and when the flocculation process was conducted at 200 rpm of mixing speed and 30 min of settling time. It was also found that the investigated operating parameters (i.e. dosage, mixing speed and settling time) did not influence much on removal of color and reduction of turbidity and COD when PAC was used as flocculant. Keywords: Flocculation; polyacrylamide (PAM); polyaluminum chloride (PAC); textile wastewater


2000 ◽  
Vol 628 ◽  
Author(s):  
Kazuki Nakanishi ◽  
Souichi Kumon ◽  
Kazuyuki Hirao ◽  
Hiroshi Jinnai

ABSTRACTMacroporous silicate thick films were prepared by a sol-gel dip-coating method accompanied by the phase separation using methyl-trimethoxysilane (MTMS), nitric acid and dimethylformamide (DMF) as starting components. The morphology of the film varied to a large extent depending on the time elapsed after the hydrolysis until the dipping of the coating solution. On a glass substrate, the films prepared by early dipping had inhomogeneous submicrometer-sized pores on the surface of the film. At increased reaction times, relatively narrow sized isolated macropores were observed and their size gradually decreased with the increase of reaction time. On a polyester substrate, in contrast, micrometer-sized isolated spherical gel domains were homogeneously deposited by earlier dippings. With an increase of reaction time, the volume fraction of the gel phase increased, then the morphology of the coating transformed into co-continuous gel domains and macropores, and finally inverted into the continuous gel domains with isolated macropores. The overall morphological variation with the reaction time was explained in terms of the phase separation and the structure freezing by the forced gelation, both of which were induced by the evaporation of methanol during the dipping operation.


2021 ◽  
Vol 232 (5) ◽  
Author(s):  
Enrique David Victor Giordano ◽  
Maria Emilia Brassesco ◽  
Paola Camiscia ◽  
Guillermo Alfredo Picó ◽  
Nadia Woitovich Valetti

2012 ◽  
Vol 627 ◽  
pp. 378-381
Author(s):  
Bi Rong Wang

Fenton pretreatment has been used for treating dye wastewater. The effects of the dos of H2O2 and FeSO4, reaction time and pH on the removal COD were investigated. It was found that, when the reaction conditions are as follows: COD 2850 mg/L dyeing wastewater, the dosage of H2O2 is 140mmol/L, FeSO4 17.02 mmol/L, pH 7.6, and reaction time 1.0 h, the CODcr of dye wastewater removal rate of up to 70%. Fenton pretreatment process of dye wastewater has a broad prospect.


2001 ◽  
Vol 44 (10) ◽  
pp. 231-236 ◽  
Author(s):  
J. Gregory ◽  
V. Dupont

Hydrolyzing coagulants are extensively used in water and wastewater treatment, often under conditions where hydroxide precipitation is important, giving “sweep flocculation”. Pre-hydrolyzed coagulants, such as polyaluminium chloride (PACl) are also widely used and have several advantages over traditional additives, such as aluminium sulfate. Their action is usually discussed in terms of cationic species and charge neutralization. However, precipitation may also be important and this aspect has not been considered in detail. The present work has compared the action of alum and three commercial PACl products on model clay suspensions. The conventional jar test procedure has been used, along with measurements of settled floc volume and dynamic monitoring of floc formation and break-up by an optical technique. The latter method gives very useful information on the nature of the flocs produced and their response to different shear conditions. It is clear from the results that the PACl products form larger and stronger flocs than alum. With all coagulants floc breakage appears to be essentially irreversible. Sediment volumes are slightly lower for flocs produced by PACl than by alum, but the value is proportional to the dosage in all cases.


2013 ◽  
Vol 64 (1) ◽  
Author(s):  
Norzita Ngadi ◽  
Nor Aida Yusoff

The study investigated the performance of chitosan and extracted pandan leaves towards treatment of textile wastewater by using flocculation process. Pandan leaves were extracted by using solvent extraction method. Flocculation process was conducted using a Jar test experiment. The effect of dosage, pH, and settling time on reduction of COD, turbidity and color of textile wastewater was studied. The results obtained found that chitosan was very effective for reduction of COD, turbidity, color and indicator for color. The best condition for COD and turbidity removal was achieved at 0.2 g dosage, pH 4 and 60 minutes of settling time. Under this condition, about 58 and 99% of COD and turbidity was removed, respectively. However, the results obtained using extracted pandan was opposite compared to the chitosan. Extracted pandan was not able to remove both COD and turbidity of the waste. 


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